Mesenchymal stem cells: a new front emerges in coronavirus disease 2019 treatment.

Currently, treating coronavirus disease 2019 (COVID-19) patients, particularly those afflicted with severe pneumonia, is challenging, as no effective pharmacotherapy for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exists. Severe pneumonia is recognized as a clinical syndrome characterized by hyper-induction of pro-inflammatory cytokine production, which can induce organ damage, followed by edema, dysfunction of air exchange, acute respiratory distress syndrome, acute cardiac injury, secondary infection and increased mortality. Owing to the immunoregulatory and differentiation potential of mesenchymal stem cells (MSCs), we aimed to outline current insights into the clinical application of MSCs in COVID-19 patients. Based on results from preliminary clinical investigations, it can be predicted that MSC therapy for patients infected with SARS-CoV-2 is safe and effective, although multiple clinical trials with a protracted follow-up will be necessary to determine the long-term effects of the treatment on COVID-19 patients.